Magento 2 module creation - Enabling without command line

<?php

use Magento\Framework\App\Bootstrap;

require __DIR__ . '/app/bootstrap.php';

$bootstrap = Bootstrap::create(BP, $_SERVER);

$obj = $bootstrap->getObjectManager();

$state = $obj->get('Magento\Framework\App\State');
$state->setAreaCode('frontend');
$key[0]='bin/magento';
$key[1]='cache:status';
$_SERVER['argv']=$key;
try {
    $handler = new \Magento\Framework\App\ErrorHandler();
    set_error_handler([$handler, 'handler']);
    $application = new Magento\Framework\Console\Cli('Magento CLI');
    $application->run();
} catch (\Exception $e) {
    while ($e) {
        echo $e->getMessage();
        echo $e->getTraceAsString();
        echo "\n\n";
        $e = $e->getPrevious();
    }
}

Run the script from magento root folder.

Magento 2 relies heavily on cli usage and does not play well with a shared hosting. It will make your life really difficult.
You could try adding a php file with this content

<?php 
shell_exec('php bin/magento setup:upgrade');

but I doubt it will work. Most probably, if you don't have ssh access, then shell_exec is disabled also.
You could try the answer from Jothibasu. It might work, but this will help you for now.
In order to have a proper magento website you will need to run a cron (you might be able to do that without ssh access though).
But the cli will save you a lot of trouble.